The most lethal feature of PDAC is the early onset of invasion and metastasis; even at the pre-cancerous pancreatic intraepithelial neoplasia (PanIN) stage, TME-derived signals such as TGF-β and HGF can induce EMT. EMT drives cells to detach from ductal structures, degrade the dense stroma and enter the circulatory system, initiating the metastatic cascade and serving as the core engine of this multi-step process (14). In this process, EMT not only reshapes the cellular phenotype in response to TME signals but also endows cells with migratory and invasive capabilities, laying the foundation for the early metastasis of PDAC (14). Ultimately, EMT provides PDAC cells (originally adherent to ductal structures) with a complete toolkit to break free from constraints and cross the dense stromal barrier unique to PDAC.

A classic hallmark of EMT is the downregulation or loss of function of E-cadherin, a core component of adherens junctions between epithelial cells that maintains junction stability through binding to p120. The loss of E-cadherin disrupts intercellular junctions in pancreatic ductal epithelial cells, relieves inhibition of Rho family GTPases and enables cells to acquire individualistic characteristics and detach from the primary tumor, representing the critical first step in initiating metastasis (15). In PDAC, EMT-TFs (particularly SNAIL1 and ZEB1) activated by TME factors such as TGF-β can directly bind to the promoter of the CDH1 gene (which encodes E-cadherin). By recruiting epigenetic modification complexes [such as histone deacetylases (HDACs) and DNA methyltransferases (DNMTs)], these TFs strongly and stably repress CDH1 transcription (16,17). This breakage of the adhesion chain allows cancer cells to escape from the primary tumor mass, creating a prerequisite for invasion (18). Concurrently, EMT is often accompanied by cadherin switching: While inhibiting CDH1 expression, EMT-TFs upregulate N-cadherin (CDH2) expression, thereby achieving functional substitution between the two cadherins. This switch is not a simple replacement of expression patterns but rather remodels cell adhesion properties; shifting from E-cadherin-mediated homophilic adhesion between epithelial cells to N-cadherin-mediated heterophilic adhesion with stromal cells [such as cancer-associated fibroblasts (CAFs)] and activating the α-ctenin/vinculin-FAK/Src signaling pathway to enhance directed adhesion strength. laying the molecular foundation for subsequent interactions with stromal cells (19). In the PDAC TME, CAFs highly express N-cadherin, which forms mechanically active heterotypic adhesions with residual E-cadherin on the surface of EMT-experienced cancer cells. Through α-catenin/vinculin-mediated force transmission, this interaction activates the focal adhesion kinase (FAK)/Src signaling pathway to enhance directed migration. Meanwhile, this stable interaction provides mechanical support and survival signals for cancer cells to traverse the dense stroma, helping them adapt to TME stress (20).

Alongside changes in cell adhesion patterns, EMT drives cytoskeletal remodeling to meet migratory demands via a TGF-β-mediated alternative splicing regulatory network: alternative splicing variants of genes such as ARHGEF11 and CTTN activate Rho family GTPase signaling, prompting the reorganization of actin from a cortical network (which maintains polarity) into stress fibers that traverse the cell. This structural transition provides the mechanical basis for directed cell movement (21). These stress fibers anchor to the ECM via integrin-mediated focal adhesions and myosin contraction generates an intracellular tension gradient. This gradient, in coordination with traction forces transmitted by integrin-focal adhesions, enables cells to overcome the resistance of the dense stroma. The precise regulation of polarized reorganization of the actin cytoskeleton and dynamic balance of focal adhesions ultimately achieves morphological adaptation to the mesenchymal-like migration mode (22). Among Rho family GTPases (key molecules regulating cell functions), RhoA and Rac1 show opposite activity changes during EMT: Rac1 activity increases markedly, while RhoA activity decreases. These two enzymes regulate the contractility and stiffness of the actin cortex (a structure maintaining cell shape) with the cell cycle; in the interphase (when cells do not divide), they reduce cortical tension to adapt to shape changes caused by the environment; in mitosis (when cells divide), they enhance cortical mechanical strength to support cell shape adjustment. This regulation enables the mechanical transition of the cytoskeleton to accurately match EMT-related phenotypes (23,24).

Another pathological challenge of PDAC is its abnormally dense fibrotic stroma, primarily composed of type I, III and IV collagen, fibronectin and hyaluronan. This stroma is synergistically deposited by tissue-resident macrophages of embryonic origin, activated pancreatic stellate cells (PSCs) and CAFs, driven by TGF-β and matrix stiffness via FAK signaling, forming a robust physical barrier (8,25,26). To breach this barrier for invasion and intravasation, cancer cells must actively degrade ECM components. Notably, the ECM in PDAC exhibits a paradoxical role: Although it is produced via synergistic deposition by pancreatic stellate cells (PSCs), cancer-associated fibroblasts CAFs and other cells, induced by tumor stimuli in the tumor microenvironment (such as TGF-β signaling, matrix stiffness), it forms a physical barrier that hinders the initial spread of tumors. Therefore, cancer cells need to overcome this barrier through EMT: EMT-related transcription factors (such as Snail, ZEB1) recruit co-activators with histone acetyltransferase activity (such as CBP/p300), thereby activating the expression of proteolytic enzymes such as matrix metalloproteinases (MMPs). These enzymes can specifically degrade ECM components such as collagen, creating pathways for cancer cell invasion (26). The MMP family plays a central role in this process: via MMP-14-mediated cascade activation (such as activating MMP-2 and MMP-9), combined with spatiotemporally specific degradation regulated by integrin/FAK signaling, MMPs act as key effectors for breaking through the dense stromal barrier (27). MMP-14 is particularly critical: it anchors to the cell membrane via its transmembrane domain and palmitoylation of Cys574 in its cytoplasmic tail further stabilizes membrane localization. Trafficking mediated by the LLY573 motif targets MMP-14 precisely to invadopodia; meanwhile, its homodimerization enhances collagenase activity, efficiently cleaving type I collagen. In coordination with the spatiotemporal degradation pattern regulated by FAK-p130cas signaling, MMP-14 creates invasive channels for cells (28).

More importantly, in the complex TME of PDAC, the EMT program establishes a destructive synergistic relationship between cancer cells and stromal cells: EMT-experienced cancer cells secrete TGF-β and platelet-derived growth factor (PDGF), which activate the transformation of PSCs into CAFs via the Smad pathway and MAPK/ERK signaling, respectively. Activated CAFs, in turn, become the primary source of matrix-degrading enzymes through high MMP expression (29,30). This bidirectional crosstalk forms a malignant positive feedback loop: EMT cells induce a CAF-mediated fibrotic TME via secretion of TGF-β, while excessive TGF-β secreted by CAFs in this microenvironment further reinforces the EMT phenotype via the SMAD pathway and non-SMAD signals (such as MAPK/ERK). Simultaneously, mechanical tension generated by ECM remodeling amplifies invasion signals via integrin/FAK signaling, paving the way for collective invasion of tumor cells (31). Thus, EMT endows cancer cells with autonomous motility and autophagy-regulated matrix degradation capabilities. Through synergistic interactions with CAFs (via TGF-β/SMAD and MAPK/ERK signaling), EMT drives PDAC progression from in situ carcinoma to invasive cancer. Additionally, via autophagy-dependent exosome release and immune evasion (to avoid immune surveillance), EMT ultimately promotes efficient metastasis to distant organs such as the liver (32).

Following EMT-mediated invasion through the dense stroma, cancer cells further acquire the ability to intravasate into the vascular system. This process is facilitated by EMT-induced upregulation of MMPs (such as MMP-14) that degrade vascular basement membrane components, as well as enhanced interactions with endothelial cells via N-cadherin-mediated adhesion (20,28). EMT thus acts as a key driver linking tumor detachment, stromal invasion and vascular entry, laying the foundation for subsequent metastatic dissemination.

EMT is the core engine driving PDAC invasion and metastasis. TGF-β-induced E-cadherin suppression (via SNAIL1/ZEB1) and N-cadherin upregulation enable adhesion switching, conferring migratory capacity. Concurrently, EMT activates MMP-14 to degrade collagen and pave invasion routes. Crucially, EMT and CAFs form a TGF-β-driven positive feedback loop: EMT cells activate CAFs, which secrete TGF-β to reinforce EMT, collectively breaching the dense stroma and enabling metastasis (Fig. 1).

After intravasation, EMT continues to regulate the survival and metastatic potential of circulating tumor cells (CTCs) during circulation and mediates successful colonization at distant organs via mesenchymal-epithelial transition (MET) reversal.

After PDAC cells invade the vascular system, they disseminate in the blood or lymphatic fluid as CTCs, the essential carriers of distant metastasis. The pre-metastatic precursor cell properties enriched in CTCs have been confirmed in PDAC studies (33,34). The harsh environment of the circulatory system requires CTCs to resist blood shear stress, activate the YAP1 pathway via platelets to resist anoikis and evade immune surveillance with the help of neutrophil extracellular traps (33). EMT enhances the survival and metastatic capacity of CTCs by downregulating epithelial markers (such as EpCAM), upregulating mesenchymal phenotypes (such as Vimentin) and activating the JNK signaling pathway, making it a key mechanism for CTCs to adapt to the circulatory environment (33,35).

Studies have found that CTCs in the peripheral blood of PDAC patients often exhibit varying degrees of EMT characteristics and their phenotypic heterogeneity is associated with TGFβ/Smad pathway activation and Snail-mediated downregulation of epithelial markers (36,37). Although cells that have fully undergone EMT exhibit enhanced motility via the RhoA/ROCK pathway: Activation of this pathway regulates actin filament contraction and focal adhesion dynamic assembly, thereby driving cytoskeletal reorganization to promote migration, while their single-cell state makes them more vulnerable to damage from blood shear stress and attack by natural killer (NK) cells (37,38). In recent years, the 'partial' EMT or 'hybrid' EMT state has been confirmed to be the phenotype with the highest metastatic efficiency: such cells acquire mesenchymal properties via Twist1/MAPK pathway activation to resist apoptosis, while retaining E-cadherin-mediated cell junctions; their plasticity is maintained by the Notch-Jagged1 signaling pathway, which sustains intercellular fate consistency through lateral induction (38).

Cells in this state achieve dual functions through unique phenotypic plasticity: On the one hand, they acquire mesenchymal characteristics (such as enhanced motility and anti-apoptotic potential) via EMT, enabling them to detach from the primary tumor and survive in the circulation (39); on the other hand, the retained E-cadherin mediates intercellular junctions, providing a structural basis for the formation of CTC clusters, which have markedly higher metastatic potential and circulatory survival rate than single CTCs (40,41).

CTC clusters enhance metastatic efficiency through synergistic mechanisms: Their aggregate structure, together with protective microthrombi formed by platelets, reduces direct damage to internal cells from fluid shear stress; meanwhile, by expressing molecules such as PD-L1 and CD47, CTC clusters inhibit T-cell function via the PD-1/PD-L1 signaling axis and block phagocytosis through the interaction between CD47 and macrophage SIRPα, thereby reducing the probability of elimination by immune surveillance (42); simultaneously, intercellular signal communication within CTC clusters (such as E-cadherin-mediated adhesion and Notch-Jagged1 signaling maintaining phenotypic plasticity) and interactions with platelets (such as TGF-β released by platelets activating Smad pathway to sustain mesenchymal properties and ADP promoting TGF-β release via platelet P2Y12 receptor) further enhance their survival capacity, making them more likely to be retained and colonized in distal capillaries (43,44).

Resisting anoikis is critical for CTC survival and EMT endows this capacity by activating pathways such as PI3K/Akt and MEK/ERK. For example, TWIST1 can upregulate Akt phosphorylation to inhibit the apoptotic program triggered by matrix detachment, while Snail enhances cell survival by regulating the expression of the anti-apoptotic protein Bcl-2 (45,46). Additionally, mesenchymal phenotype-related receptors (such as integrins) can bind to platelets or soluble matrix proteins (such as PDGF and VEGF) in the circulation, forming a protective microenvironment that further reduces the risk of apoptosis and lays the foundation for metastasis (47,48).

The final step of the metastatic cascade, and the key to the formation of metastatic lesions, is the successful colonization of CTCs in distant organs. To proliferate in the new microenvironment and form macroscopically visible secondary tumors, disseminated cancer cells must undergo MET, the reverse process of EMT. This process restores epithelial cell polarity and intercellular adhesion capacity, enabling cells to integrate into new tissues and proliferate in an orderly manner (49,50). This phenotypic plasticity depends not only on the dynamic regulation of transcription factors (such as Snail and Twist) but also on epigenetic reprogramming (such as histone modification and DNA methylation) and the regulation of mRNA stability by RNA-binding proteins (51,52). For example, lncRNA H19 maintains the balance of cell plasticity during EMT/MET switching by sponging miR-200b/c and let-7b (49).

The core of phenotypic plasticity lies in the dynamic adaptation to the pressure of the metastatic microenvironment: sustained TGF-β signals in the primary tumor induce an EMT-mediated mesenchymal phenotype (that is, a phenotype with low E-cadherin expression and high vimentin expression) in CTCs, enabling them to resist shear stress and immune attack in the circulation; when CTCs reach the metastatic site, epithelial differentiation signals (such as BMPs) in the microenvironment can activate the SMAD pathway, triggering MET to rebuild epithelial structures and support colonization and proliferation (53,54). This bidirectional switching mechanism allows cancer cells to resist shear stress and immune attack in the circulation with a mesenchymal phenotype and rebuild epithelial structures via MET to support proliferation during colonization. Histological analysis of PDAC liver metastases confirms that metastatic tumor cells transmit the CD44v6/C1QBP complex via exosomes, remodeling the hepatic fibrotic microenvironment and maintaining an epithelial-like differentiated state, providing direct evidence for the occurrence of MET (55). In summary, from driving invasion of the primary tumor, to endowing treatment resistance and stem cell phenotypes and finally to ensuring the circulatory survival of CTCs and their eventual distant colonization, EMT and its reverse process MET together form a core axis the entire metastatic process of PDAC. This remarkable cellular plasticity allows PDAC cells to flexibly adapt to various environmental pressures, making it one of the fundamental reasons for the difficulty in radical treatment-and thus an extremely attractive therapeutic target (Fig. 2).

Beyond driving the entire metastatic cascade (detachment, invasion, intravasation, circulation and colonization), EMT also plays a pivotal role in mediating therapy resistance in PDAC; this mechanism is closely linked to EMT-induced stemness acquisition and phenotypic plasticity, independent of metastatic localization.

PDAC exhibits extreme resistance to current chemotherapy (such as gemcitabine and oxaliplatin) and radiotherapy, which contributes to its high mortality. Accumulating evidence indicates that extracellular vesicles derived from CAFs transmit molecules such as miR-146a (which activates Snail) and circFARP1 [which activates the LIF/signal transducer and activator of transcription 3 (STAT3) axis], mediating a mutually reinforcing vicious cycle among the EMT program, acquisition of CSC properties and treatment resistance, collectively forming the biological basis for PDAC treatment failure (33,56,57).

Cancer stem cells (CSCs) are subpopulation of tumor cells with self-renewal capacity and multi-lineage differentiation potential. They maintain stemness by activating signaling pathways such as WNT/β-Catenin, Notch and TGF-β and serve as core drivers of tumor initiation, recurrence and metastasis (58,59). In PDAC, cell subpopulations expressing CD44⁺/CD24⁺/EpCAM⁺, CD133⁺, or high aldehyde dehydrogenase 1 (ALDH1) activity have been confirmed to be enriched in CSCs. Among these markers, CD133 expression is regulated by hypoxia-inducible factor 1α (HIF-1α), CD44 maintains stemness via the WNT/β-Catenin pathway and high ALDH1 activity is associated with the antioxidant phenotype and drug resistance of CSCs (60,61). A breakthrough finding is that in PDAC cells, TGF-β induces EMT via the Smad pathway, activating transcription factors such as Snail and ZEB1 and enabling differentiated non-stem cancer cells to acquire CSC characteristics; conversely, knockout of these EMT-TFs markedly impairs the self-renewal capacity and in vivo tumorigenicity of CSCs by inhibiting stemness-maintaining pathways such as WNT/β-Catenin (58,62).

Among EMT-TFs, ZEB1 plays a core integrative role: the bidirectional negative feedback loop formed between ZEB1 and the miR-200 family not only drives EMT phenotypic switching but also maintains cell stemness by stabilizing the expression of the stem cell factor Sox2; meanwhile, the direct interaction between ZEB1 and YAP1 can respond to TGF-β signals to activate downstream target genes, thereby coordinately regulating stem cell pluripotency (63). The key mechanism lies in the transcriptional inhibition of stemness-suppressing microRNAs (such as the miR-200 family) by ZEB1/2; in turn, the miR-200 family forms a mutually inhibitory feedback loop by targeting the 3' untranslated region (3'UTR) of ZEB1'2 and further indirectly regulates CSC properties by modulating these EMT-TFs (64). Specifically, the miR-200 family and ZEB1/2 form a mutually inhibitory negative feedback loop; ZEB1/2 transcriptionally inhibit miR-200 expression, while miR-200 inhibits ZEB1/2 function by targeting their 3'UTR; simultaneously, miR-200 can directly target and inhibit the stemness factor BMI1, thereby regulating CSC properties (65). Thus, high ZEB1 expression in PDAC enhances the activated phenotype of stromal myofibroblasts, activates KRAS and its downstream PI3K/AKT pathway in cancer cells via paracrine signals, disrupts the balance of the tumor microenvironment, accelerates the progression of PDAC from pre-cancerous lesions to malignant tumors and markedly enhances its in vivo tumor-initiating capacity (66).

The close association between EMT and CSCs is a key reason for the broad-spectrum resistance of tumors to treatment. EMT can induce cells to acquire CSC-like properties by activating stem cell-related signaling pathways [such as Notch and Hedgehog (Hh)] and downregulating epithelial markers (such as E-cadherin) while upregulating mesenchymal markers (such as Id-1, α-SMA), which specifically includes temporary entry into a dormant state (cell cycle arrest). Most chemotherapeutic drugs, such as gemcitabine, primarily target rapidly proliferating cells, allowing these dormant cells to evade drug attack and become the source of recurrence after treatment (67). Secondly, the EMT program can enhance cell survival signals by activating pro-survival signaling pathways such as PI3K/AKT and increase the apoptotic threshold by upregulating anti-apoptotic molecules (such as Bcl-xL) and inhibiting pro-apoptotic factors (such as BOK), making cells more likely to survive DNA damage induced by drugs or radiation (68).

In pancreatic cancer, EMT is a key mechanism mediating resistance to chemotherapy and radiotherapy and it affects the response of tumor cells to treatment through a multi-dimensional regulatory network. EMT-TFs such as ZEB1 play a central role: High ZEB1 expression is closely associated with gemcitabine resistance and ZEB1 can maintain the EMT phenotype and reduce drug sensitivity by inhibiting the miR-200 family to form a negative feedback loop; conversely, ZEB1 knockdown can markedly reverse this process (69,70). Additionally, EMT-induced metabolic reprogramming provides an energy basis for drug resistance: PDAC cells with ZEB1 deficiency cannot compensatorily enhance glycolysis when oxidative phosphorylation is inhibited, making them sensitive to metabolic stress; by contrast, EMT-activated cells maintain energy supply by upregulating glucose transporters [such as Glucose Transporter 3 (GLUT3)] and the Warburg effect, thereby tolerating metabolic stress induced by chemotherapeutic drugs (69). In terms of radioresistance, EMT achieves resistance by enhancing DNA damage repair capacity: ZEB1 can directly bind to the Ataxia Telangiectasia Mutated Protein (ATM) promoter and form a complex with p300/PCAF to promote ATM expression; meanwhile, ZEB1 stabilizes CHK1 by sequestering the deubiquitinase USP7, accelerating DNA damage repair to reduce radiation-induced cell death (69); furthermore, radiotherapy itself can upregulate EMT-TFs such as ZEB1 and Snail by activating pathways such as TGF-β and NF-κB, further exacerbating resistance (71). The involvement of the TME is another important aspect: Cytokines such as TGF-β and IL-6 secreted by CAFs can induce EMT, promoting resistance of PDAC cells to chemotherapeutic drugs; targeting paracrine signals between CAFs and tumor cells can partially reverse this resistance (69,71). Notably, while EMT is not necessary for metastasis, it clearly induces chemotherapy resistance in pancreatic cancer, this property provides a theoretical basis for EMT-targeted therapeutic strategies (72). Meanwhile, EMT is closely associated with the CSC phenotype: EMT-TFs can maintain the stemness of CSCs, making them less sensitive to radiotherapy and chemotherapy and forming a drug-resistant cell population (73).

The EMT-stemness-therapy resistance axis is central to PDAC malignancy. TGF-β-driven ZEB1 suppresses miR-200 and activates WNT/β-Catenin, conferring stemness (such as CD44⁺/CD133⁺) and cell-cycle arrest to evade chemotherapy (such as gemcitabine) and immune targeting. Concurrently, ZEB1 enhances DNA repair (ATM/CHK1) and metabolic reprogramming (Warburg effect) for broad resistance. Critically, therapeutic targeting faces major limitations: EMT-related molecules (such as ZEB1) have essential physiological roles in normal tissues, risking off-target toxicity; and discrepancies between preclinical models and human responses hinder clinical translation, necessitating more precise intervention strategies (Fig. 3).

EMT-TFs are the core hubs of the regulatory network. After integrating upstream signals (such as pathways mediated by TGF-β and IL-6), they act as terminal effectors to directly execute gene expression switching, binding to the promoters of target genes to inhibit epithelial programs (such as the CDH1 gene encoding E-cadherin) and activate mesenchymal programs (75). In pancreatic cancer, the Snail, ZEB and Twist families are key executors of this process, playing indispensable roles.

EMT-TFs [Snail, ZEB, Twist and Paired Related Homeobox (PRRX) families] rely on conserved domains (zinc finger, bHLH and homeodomain) for DNA binding and transcriptional regulation. Their core commonality is regulating EMT via E-box binding, suppressing epithelial markers (such as CDH1) and activating mesenchymal genes, alongside forming miRNA negative feedback loops. Functionally divergent due to domain differences: Snail recruits co-repressors via SNAG domain, ZEB interacts with YAP/AP-1, Twist requires dimerization and PRRX synergizes with Twist to enhance invasiveness (76,77). Downstream, they form a bipolar target network: CDH1 is directly repressed by Snail/ZEB/Twist (a key EMT-initiating event), while mesenchymal targets (VIM, CDH2, MMP9) and fibroblast-related genes (activated by PRRX1-TWIST1) collectively drive PDAC progression (78,79).

As a core EMT transcription factor, Snail1 drives the malignant progression of pancreatic cancer through a multi-level regulatory network; its abnormal function is closely associated with the acquisition of the EMT phenotype and enhanced invasive/metastatic capacity. At the signaling pathway level, the TGF-β1-Smad2/3 pathway upregulates Snail1 via Numb-PRRL activation and synergizes with Notch1 to enhance the EMT phenotype, characterized by downregulation of E-cadherin and upregulation of N-cadherin and Vimentin (80). The WNT/β-catenin pathway forms a positive feedback loop with Snail1:STMN2 activates the WNT/β-catenin pathway (promoting β-catenin nuclear translocation to bind TCF transcription complex) to upregulate Snail1 expression, while the nuclear β-catenin/TCF complex in turn transactivates STMN2 gene expression; their mutual promotion collectively reinforces EMT and proliferation (81). At the metabolic level, RHOF enhances glycolysis via the c-Myc-PKM2 axis and lactic acid induces lactylation and nuclear translocation of Snail1 to drive EMT (82); epigenetically, miR-34a directly targets Snail1 mRNA to inhibit its expression, weakening the invasive capacity of cancer cells (83).

The protein stability of Snail1 is dynamically regulated by the ubiquitin-proteasome system: F-box/LRR-repeat protein 7 inhibits EMT by ubiquitinating and degrading Snail1 (84), while TGF-β-induced ubiquitin-specific peptidase 27X (USP27X) stabilizes Snail1 via deubiquitination, enhancing its pro-EMT and chemoresistant functions (85). Further studies have shown that 17 E3 ubiquitin ligases (such as FBXL14 and βTrCP1, which mediate Snail1 degradation via ubiquitination) and 23 deubiquitinating enzymes (such as USP47 and DUB3, which stabilize Snail1 via deubiquitination) together form a regulatory network for Snail1 protein stability; in addition, proteins such as COP9 signalosome subunit 2 (CSN2, not β-casein) can indirectly maintain Snail1 stability by inhibiting the activity of E3 ubiquitin ligases (86).

Phosphorylation regulation exhibits spatiotemporal specificity: Glycogen synthase kinase 3 beta (GSK3β) phosphorylates the Ser-rich domain (SRD) in the nucleus to promote Snail1 nuclear export and synergizes with CK1ε in the cytoplasm to phosphorylate Snail1 and form a degradation motif; by contrast, kinases such as ATM and ERK2 phosphorylate specific sites in the nucleus, which can recruit Heat shock protein 90 to stabilize Snail1, reflecting the effect of subcellular localization on function (86). Modifications such as acetylation (for instance, CBP-mediated acetylation of Snail1 at Lys146/187, which enhances its transcriptional activation function and inhibits degradation) and glycosylation (such as O-GlcNAc modification at Ser112, which blocks GSK3β-mediated phosphorylation and degradation) further regulate Snail1's transcriptional activity and stability; its N-terminal intrinsically disordered region enables it to flexibly bind various regulatory factors (such as E3 ligases, deubiquitinating enzymes), making it a hub for integrating EMT signals (86).

During the occurrence and development of pancreatic cancer, Snail1 acts as a core driver in the progression of precursor lesions. Inhibition of Snail1 via gene knockout or drugs (such as GN25) can effectively delay the occurrence and development of pancreatic intraepithelial neoplasia (PanINs) and reduce acinar-ductal metaplasia (ADM) after pancreatic injury, suggesting its significant potential for early intervention in pancreatic cancer (87). From the perspective of downstream effects of signal transduction, the execution of the EMT phenotype mediated by Snail1 depends on the classical BMP signaling pathway, which regulates the expression of downstream target genes through synergy with SMAD4, ultimately achieving EMT-related invasive and metastatic phenotypes (88). At the clinical level, the metastasis suppressor Raf kinase inhibitor protein (RKIP) is markedly negatively correlated with Snail1 expression: high RKIP expression is often associated with a favorable prognosis in pancreatic cancer patients, while high Snail1 expression predicts disease progression and poor outcomes, this association provides an important molecular marker for prognosis evaluation of pancreatic cancer (39).

The ZEB family, especially ZEB1, serves as a core driver of EMT and stem cell properties in pancreatic cancer. It participates in multiple key links of tumor malignant progression through a complex regulatory network and its abnormal activation is driven by the synergy of multi-level upstream signals, non-coding (nc)RNA networks, inflammatory pathways and cell plasticity regulation. In the early stage of tumorigenesis, ZEB1 is a key driver of the progression of pancreatic precursor lesions: in the KRAS and p53 mutant pancreatic cancer model (KPC) mouse model (carrying KRAS and p53 mutations), deletion of ZEB1 can markedly reduce the number and grade of ADM and PanINs; in the KRAS mutant pancreatic cancer model (KC) model (carrying KRAS mutation but no p53 mutation), deletion of ZEB1 more markedly inhibits the formation of KRAS-driven early lesions, highlighting its importance in the initiation stage of pancreatic cancer (63). In terms of regulatory mechanisms: at the epigenetic level, enhancer of zeste homolog 2 (EZH2) inhibits miR-139-5p via lysine 27 trimethylation on histone H3 (H3K27me3), thereby relieving the targeted inhibition of ZEB1/2 by miR-139-5p (89); in the inflammatory microenvironment, macrophage migration inhibitory factor (MIF) downregulates miR-200b to enhance ZEB1/2 expression (90), while NF-κB directly binds to the ZEB1 promoter to promote its transcription (91). In signaling pathways, vasohibin 2 (VASH2) activates the Hh pathway to upregulate ZEB1/2 (92),TGF-β-induced EMT is dependent on ZEB1; ZEB1 deletion renders PDAC cells unable to undergo phenotypic switching in response to TGF-β stimulation, as 91% of TGF-β-regulated genes require ZEB1 involvement (63). ZEB1 forms a negative feedback loop with the miR-200 family: ZEB1 deletion leads to high miR-200c expression, which in turn inhibits stem cell markers such as Sox2 and markedly reduces sphere formation capacity and tumor-initiating potential (63).

Functionally, ZEB1 endows pancreatic cancer with a malignant phenotype by maintaining cell plasticity: ZEB1 deletion fixes cells in the epithelial phenotype, losing the ability to switch between epithelial and mesenchymal phenotypes and resulting in the inability of the invasive front to undergo dedifferentiation. Metabolically, ZEB1 deletion markedly reduces oxidative phosphorylation and glycolytic reserves, rendering cells unable to adapt to changes in TME energy demands. Unlike Snail and Twist, ZEB1 is necessary for metastasis in the KPC model, ZEB1 deletion almost completely abolishes lung colonization capacity, while Snail deletion has no such effect, reflecting the non-redundancy of EMT-TFs. Clinically, high ZEB1 expression is associated with the 'quasi-mesenchymal' subtype of pancreatic cancer, while ZEB1 deletion enriches features of the 'classical' subtype (which has an improved prognosis) (63). The malignant function of ZEB1 can be counter regulated by SCAND1, which forms a complex with myeloid zinc finger 1 (MZF1) to inhibit ZEB1/2 expression (93). By regulating precursor lesion progression, cell plasticity, stem cell properties and metabolic adaptation, ZEB1 serves as a core node of EMT in pancreatic cancer and its unique role provides a specific target for targeted therapy.

The Twist family (Twist1 and Twist2), as core members of basic helix-loop-helix (bHLH) transcription factors, play key roles in EMT of pancreatic cancer through multi-dimensional regulation. Their functions are not only related to cell plasticity in embryonic development but also involved in malignant progression driven by the tumor microenvironment (94,95). Twist1 and Twist2 both bind to the promoters of epithelial marker genes such as E-cadherin to inhibit their expression, while upregulating mesenchymal markers such as Vimentin and N-cadherin, promoting the transformation of epithelial cells to an invasive phenotype (95). In terms of regulatory mechanisms, the Twist family is precisely regulated by tumor microenvironment signals: Hypoxia activates Twist1 transcription by stabilizing HIF-1α and this pathway is associated with lymph node metastasis and poor prognosis of pancreatic cancer (95,96); TGF-β upregulates SOX5 via a Smad-dependent pathway to enhance Twist1 expression and also synergizes with RAS signals via STAT3 and ETS1/2 to strengthen its expression (94,95); Aurora kinase A (AURKA) phosphorylates Twist1 at sites S123, T148 and S184 to inhibit its ubiquitination-mediated degradation and enhance its activity; meanwhile, Twist1 maintains AURKA protein levels by inhibiting its ubiquitination degradation and the two form a positive feedback loop to amplify the EMT effect (97). In downstream effects, Twist1 promotes invasion and cisplatin resistance by inducing MMP2 and GDF15 (98) and interacts with Ring1B and EZH2 to downregulate tumor suppressor genes and enhance proliferation (96). Twist2 is regulated by HIF-2α, specifically binds to the E-cadherin promoter to inhibit its expression and is negatively correlated with E-cadherin expression (99). Additionally, arginine deprivation (that is, reducing extracellular arginine levels via arginine deiminase or other means to inhibit arginine-dependent pancreatic cancer cells from acquiring this essential amino acid) can downregulate Twist expression, thereby inhibiting EMT (100) and miR-539 directly targets Twist1 mRNA to inhibit its translation (101). In metastasis biology, Twist1-mediated EMT endows pancreatic cancer cells with the migratory ability to detach from the primary tumor, while colonization of metastatic lesions depends on the downregulation of Twist1 and activation of MET. This dynamic switching reflects the spatiotemporal specificity of the Twist family in different stages of metastasis (95).

As the core EMT initiator, Snail1's stability is regulated by TGF-β-activated deubiquitinase USP27X; TGF-β upregulates USP27X, which then stabilizes Snail1 via deubiquitination. Notably, Snail1 positively feeds back on TGF-β (directly promoting TGF-β transcription or indirectly enhancing its signaling), forming a 'TGF-β-USP27X-Snail1' loop that continuously strengthens E-cadherin inhibition and mesenchymal phenotype acquisition to sustain tumor progression (85). ZEB1/2 inhibits the epithelial splicing regulatory proteins ESRP1/2, promoting the expression of the fibroblast growth factor receptor-3 IIIc subtype; the latter activates the MEK-ERK-ETS1/2 pathway to feedback and maintain high expression of ZEB1/2, forming an independent self-sustaining loop. Meanwhile, ZEB1/2 is functionally complementary to Snail1 (rather than co-expressed), jointly mediating EMT plasticity (63). In some pancreatic cancer cells, Slug and Snail1 exhibit a synchronized regulatory pattern in their expression; specifically, both are often regulated by upstream regulatory factors (such as RAB11FIP1) to be simultaneously upregulated or downregulated; and these two factors can synergistically respond to TGF-β signals, thereby inducing the epithelial-mesenchymal transition (EMT) process (102).

Cross-regulation between the Twist family and other EMT transcription factors further amplifies network effects: in a hypoxic environment, HIF-1α can simultaneously induce the expression of Twist1 and Snail1; among them, Twist1 enhances chromatin modification by binding to Ring1B and EZH2, synergizing with Snail1 to strengthen the transcriptional inhibition of E-cadherin (96); ZEB1 and Twist1 exhibit functional differentiation: ZEB1 mainly regulates the phenotypic plasticity and metastatic colonization capacity of tumor cells, while Twist1 focuses more on driving invasive capacity and chemotherapy resistance (63,72). A key feedback loop also includes the mutual stabilization between Twist1 and AURKA: AURKA phosphorylates Twist1 to inhibit its ubiquitination and degradation, while Twist1 in turn prevents AURKA degradation, forming a positive feedback loop that amplifies the EMT effect (102). Additionally, the miR-200 family acts as a core negative regulator that can simultaneously target ZEB1/2 and Twist1; the tumor suppressor Par-4 constructs a 'Par-4-miR-200c-ZEB1'Twist1/ negative feedback loop by upregulating miR-200c, limiting excessive EMT activation (103). The synergy of this network is also reflected in the commonality of upstream regulation:arginine deprivation can synchronously downregulate the expression of the Snail, Slug and Twist families (98); overexpression of Dual-specificity tyrosine-phosphorylation-regulated kinase 2 indirectly affects the Snail/Slug-mediated EMT process by promoting the ubiquitination and degradation of Twist (104). These findings further confirm the close associations of various transcription factors within the network.

The regulatory roles of Snail, ZEB and Twist families, core EMT-TF hubs, in pancreatic cancer (PC) are analyzed in depth, with multi-dimensional mechanisms clearly elaborated. For Snail1, its activity is modulated by TGF-β/WNT signaling pathways, metabolic lactylation and post-translational modifications including ubiquitination and phosphorylation. ZEB1 exhibits non-redundant functions, particularly in metastasis (a unique trait validated in KPC models) and PC subtype switching. The Twist family, dependent on hypoxia/HIF-1α signaling, regulates cell invasion and exhibits spatiotemporal specificity in MET during metastasis.

Critical findings cover crosstalk between EMT-TFs, such as the TGF-β-USP27X-Snail1 positive feedback loop and functional differentiation between ZEB1 and Twist1. Negative regulatory networks, mediated by miR-200 and Par-4, are also highlighted. Clinically, the associations of these TFs with PanIN progression, prognostic evaluation (such as RKIP-Snail1 correlation) and therapeutic potential (such as GN25, arginine deprivation) provide practical value. This comprehensive network analysis enhances understanding of PC EMT plasticity and lays a theoretical foundation for developing targeted therapies (Fig. 4).

The initiation and maintenance of EMT are driven by the continuous activation of multiple upstream signaling pathways, forming a complex regulatory network. Directly targeting the source of these signals represents a fundamental strategy to inhibit EMT and its associated malignant phenotypes in pancreatic cancer. Current research has focused on several key pathways, with the TGF-β pathway being one of the most intensively studied. The TGF-β signaling pathway is a potent inducer of EMT and its aberrant activation is closely linked to disease progression and poor prognosis (57). Clinical translation efforts are exploring combinations, such as TGFβRI inhibitor with nal-IRI/5-FU/LV chemotherapy, in phase Ib/II trials. Preclinical studies showed that this combination could inhibit tumor invasion and prolong survival in mouse models by inducing the tumor suppressor gene CCDC80 and blocking EMT (170). Repurposed drugs have also shown unexpected efficacy; the antifungal agent itraconazole suppresses the TGF-β/SMAD2/3 pathway to inhibit EMT, invasion and migration (171), while the NSAID indomethacin blocks TGF-β-mediated EMT by upregulating E-cadherin and downregulating N-cadherin and Snail (172). The regulatory network is highly complex, involving molecules such as Menin, which enhances TGF-β-mediated EMT by inhibiting C/EBPβ and autocrine TGF-β1, which can form a self-sustaining feed-forward loop via the ALK5-MEK-ERK signal, antagonizing the effects of exogenous TGF-β1 (173,174). Furthermore, super-enhancers can regulate TGFBR2 expression, offering an epigenetic target (175). Natural products provide additional resources; extracts from Cynanchum paniculatum inhibit EMT by suppressing the TGF-β1/Smad2/3 pathway (176) and baicalein disrupts the TGF-β/FTO/ZEB1 axis by downregulating the m6A demethylase FTO, reducing ZEB1 mRNA stability (177). However, the dual role of TGF-β as both a tumor suppressor and promoter necessitates careful consideration, as some agents such as calycosin can inhibit proliferation but paradoxically promote EMT by upregulating TGF-β1 (178). A multi-faceted intervention system has thus been established, encompassing TGFβRI inhibitors, approved drugs, natural compounds and combination therapies with chemotherapy to improve drug penetration and clinical translation potential.

Beyond TGF-β, the Wnt/β-catenin and Hh pathways are critical targets. The Wnt/β-catenin pathway is inhibited by various natural products: oridonin suppresses the pathway and reduces β-catenin levels to inhibit migration and EMT (179). Trametes robiniophila (Huaier) extract inhibits proliferation, migration and EMT by downregulating β-catenin (180) and high-dose vitamin C blocks invasion and metastasis by suppressing Wnt/β-catenin-mediated EMT (181). At the molecular level, restoring the expression of the Wnt antagonist DKK3 blocks hypoxia-induced nuclear translocation of β-catenin and reverses EMT, enhancing gemcitabine's effect (182). Silencing molecules such as LRRFIP1 enhances β-catenin phosphorylation and reduces its nuclear localization, while silencing GPX2 downregulates key Wnt pathway molecules, both effectively reversing the EMT phenotype (183,184). Similarly, CHRNB2 exerts anti-tumor effects by downregulating β-catenin pathway activity via a non-acetylcholine-dependent mechanism (185). Epigenetic regulation also plays a role, as TET1 catalyzes DNA hydroxymethylation in the SFRP2 promoter, activating this Wnt inhibitor and blocking both canonical and non-canonical Wnt signaling (186). The Hh pathway maintains cancer stem cell properties and promotes EMT by regulating transcription factors such as Gli. Curcumin exerts multi-target effects, reversing hypoxia-induced EMT by suppressing Hh pathway activation (downregulating SHH, SMO, GLI1) and inhibiting crosstalk between CAFs and tumor cells (107,128,187). The resveratrol derivative triacetyl resveratrol (TCRV) inhibits EMT transcription factors such as Zeb1 by upregulating the miR-200 family and simultaneously inhibits the SHH pathway (188). Another natural product, α-mangostin, targets Hh pathway molecules (Gli1 and Smoothened) and core EMT-TFs (Snail and Slug); when encapsulated in PLGA nanoparticles, it effectively targets Shh pathway-related genes in vivo, reducing cancer stem cell markers and inhibiting tumorigenesis (189,190). Sedum sarmentosum Bunge extract also downregulates Hh pathway activity (191). A significant challenge is the compensatory activation of other pathways; for instance, Hh pathway inhibitors (SHhi) can improve drug delivery by enhancing vascular patency but may induce an FGF-driven EMT phenotype. This can be addressed by a dual inhibition strategy combining SHhi with FGFR inhibitors such as infigratinib, which reverses EMT while retaining improved vascular permeability (192).

Interventions targeting other key pathways, such as PI3K/Akt/mTOR and MAPK/ERK, further enrich the therapeutic arsenal. The PI3K/Akt/mTOR pathway is inhibited by agents such as the Aurora kinase A inhibitor alisertib, which reduces N-cadherin and upregulates E-cadherin to block EMT while inducing cell cycle arrest and autophagy (193). Natural products such as betulinic acid and irisin inhibit EMT and stemness by activating AMPK to suppress mTOR signaling (194,195) and plumbagin inhibits the PI3K/Akt/mTOR pathway while synergistically regulating p38 MAPK and AMPK activation (196). Inhibiting KIN17 downregulates this pathway, upregulating E-cadherin and reducing vimentin and N-cadherin (197), while arsenic trioxide reverses EMT and enhances chemosensitivity by inhibiting TIMP1-mediated PI3K/Akt/mTOR activation (198). The MAPK/ERK pathway is another key target. Curcumin inhibits IL-6-mediated ERK and NF-κB phosphorylation by suppressing PSC activation and IL-6 secretion under hypoxia, thereby disrupting tumor-stroma crosstalk (199). HNRNPA2B1 promotes EMT by activating the ERK/Snail axis (200), whereas miR-338-5p inhibits the EMT process by targeting EGFR and blocking EGF-induced MAPK/ERK signaling (201). The TAp73 protein inhibits basal and TGF-β-induced ERK activation in a SMAD4-dependent manner, upregulating E-cadherin and downregulating Snail to inhibit migration (202). Targeting receptor tyrosine kinases such as MET and AXL is also promising. The inhibitor NPS-1034 targets the MET/PI3K/AKT axis to suppress EMT and migration, shows synergistic effects with chemotherapy and exhibits immunomodulatory potential by inducing type I interferon and TNF (203). Similarly, a novel AXL/triple angiokinase inhibitor effectively suppresses AXL and lung metastasis, with its mechanism involving EMT inhibition (204). Furthermore, inhibiting the HGF/c-MET pathway not only directly inhibits tumor growth but also enhances cytotoxic T-cell infiltration by reducing TGF-β secretion, linking EMT inhibition to immune regulation (205).

In summary, a comprehensive intervention system targeting upstream signaling pathways of EMT has been established (Table I). This system includes diverse strategies: Blocking the TGF-β pathway with inhibitors and repurposed drugs, targeting the Wnt/β-catenin and Hh pathways with natural products, molecular interventions and combination therapies and inhibiting pathways such as PI3K/Akt/mTOR and HGF/c-MET with specific inhibitors that can synergize with chemotherapy. These multi-dimensional approaches, validated in preclinical studies, aim to reverse the invasive phenotype, restore treatment sensitivity and inhibit metastasis, providing a strong rationale for their clinical translation to address therapeutic resistance in pancreatic cancer.

In addition to blocking upstream signals, directly targeting the core molecules that execute the EMT program, specifically EMT-transcription factors (EMT-TFs) and the epigenetic mechanisms governing their expression, represents a more precise therapeutic strategy.

A primary approach involves inhibiting key EMT-TFs such as Snail, Slug, ZEB and Twist. This can be achieved through diverse mechanisms. For instance, miRNAs offer precise regulation: miR-34a directly targets Snail1 and Notch1 (83), miR-539 inhibits TWIST1 (101) and miR-200b-3p suppresses ZEB1 (204). Nutrient deprivation strategies, such as arginine deprivation, can simultaneously downregulate multiple EMT-TF families (Snail, Slug and Twist) while upregulating E-cadherin and inhibiting invasion (100). Natural products also exhibit multi-target effects; α-mangostin inhibits Snail and Slug (190), while the resveratrol derivative TCRV targets Snail, Slug and Zeb1 (188). Furthermore, the protein DACH1 can directly bind to SNAI1 to inhibit its transcriptional activity, thereby blocking EMT and promoting apoptosis (207). These strategies collectively reverse the EMT phenotype by upregulating epithelial markers and downregulating mesenchymal markers.

Beyond direct TF targeting, interventions against epigenetic and post-transcriptional mechanisms have emerged as powerful tools. ncRNAs function as critical regulators: lncRNA GAS5 acts as a ceRNA for miR-221 to upregulate SOCS3, reversing EMT and gemcitabine resistance (208), whereas LINC00958 promotes EMT by sponging miR-330-5p (209). Conversely, lncRNA GATA6-AS1 inhibits EMT by reducing SNAI1 mRNA stability in an m6A-dependent manner by inhibiting FTO (210). The m6A modification itself is a key regulatory layer; the 'eraser' FTO promotes EMT and can be targeted for intervention (212) and the 'demethylase' ALKBH5 exerts anti-tumor effects by demethylating mRNAs of iron metabolism regulators, indirectly leading to SNAI1 degradation (211). Histone modifications are another major target. HDAC inhibitors, such as a novel dual HDAC2/6 inhibitor and the pan-HDAC inhibitor LAQ824, can reverse TGF-β-induced EMT, induce apoptosis and enhance antigen presentation (212,213). Similarly, the histone methyltransferase inhibitor DZNep reshapes miRNA expression to block the TGF-β signaling pathway and associated EMT (214,215).

In summary, a two-dimensional intervention system has been established, encompassing the direct inhibition of EMT-TFs and the regulation of their epigenetic landscape (Table II). Preclinical studies confirm that these strategies can effectively reverse the EMT phenotype, weaken tumor stemness and invasive capacity and provide precise molecular targets for overcoming therapeutic resistance in pancreatic cancer.

EMT not only alters the characteristics of cancer cells themselves but also reshapes their interactions with the TME, particularly with CAFs and the ECM. Disrupting this crosstalk is therefore a critical strategy to inhibit metastasis.

Targeting tumor stroma and ECM: The dense fibrotic stroma of PC acts as a physical barrier to drug penetration and actively drives EMT and immune suppression through the secretion of various factors (224). Therapeutic strategies targeting stromal components have shown promising results. For instance, the oncolytic adenovirus HEmT-DCN/sLRP6 co-expresses decorin (to degrade ECM) and a Wnt decoy receptor (sLRP6), thereby improving drug penetration and directly inhibiting the Wnt/β-catenin pathway to block EMT (225). In clinical translation, RNA oligonucleotide STNM01, which targets carbohydrate sulfotransferase 15 (CHST15), has been shown in phase II trials to increase tumor-infiltrating T cells and improve patient survival (226). Additionally, inhibiting YAP expression can reduce connective tissue growth factor secretion, suppressing CAF activation and tumor-stroma interactions (227).

Blocking key tumor-stroma signaling molecules: Beyond the physical stroma, blocking key signaling molecules between tumor and stromal cells is equally important. Pharmacological inhibition of the Gas6/AXL axis, primarily produced by tumor-associated macrophages and CAFs, can partially reverse EMT and activate NK cells to inhibit metastasis (228). Similarly, a nanotechnology-delivered CXCL13 'trap' can counteract the dual effects of this chemokine, which recruits immunosuppressive regulatory B cells (Bregs) and directly stimulates EMT, thereby inhibiting tumor growth (229). Furthermore, targeted inhibition of the HGF/c-MET pathway has demonstrated stronger anti-metastatic activity than standard chemotherapy in animal models (230). These strategies highlight the potential of simultaneously reversing the EMT phenotype and activating anti-tumor immunity.

Given the complexity of pancreatic cancer, combining EMT-targeted strategies with conventional therapies is essential to overcome resistance and achieve synergistic effects (Table III).

Sensitization to chemotherapy/radiotherapy: Reversing EMT can resensitize tumors to chemotherapy and radiotherapy. Nanotechnology platforms enable effective co-delivery; for instance, EGFR-targeted micelles co-delivering gemcitabine and miR-205 can inhibit the growth of resistant tumors and reduce EMT (231). Natural products also show promise in combination regimens. β-sitosterol and epigallocatechin-3-gallate (EGCG) both synergize with gemcitabine by inhibiting the AKT/GSK-3β pathway and regulating EMT-related phenotypic switching, respectively (232,233). The TGM2 inhibitor GK921 enhances cisplatin-induced apoptosis by inhibiting EMT (234), while hyperthermia can restore gemcitabine sensitivity in resistant cells by reversing EMT (235). In radiotherapy, the pan-VEGFR inhibitor cediranib can directly inhibit EMT and enhance radiosensitivity (236).

Combination with immunotherapy to remodel the immune microenvironment: Combining EMT inhibition with immunotherapy represents another promising direction. The pan-HDAC inhibitor LAQ824 not only blocks EMT but also upregulates MHC-I molecules to enhance antigen presentation and tumor immunogenicity (213). Inhibiting the HGF/c-MET pathway can reduce TGF-β secretion, thereby relieving immunosuppression and increasing cytotoxic T-cell infiltration in the TME (205). Furthermore, a bispecific nanobody targeting PD-L1 and CXCR4 can delay EMT and disrupt the immunosuppressive TME, promoting T cell infiltration (224). These approaches aim to transform 'cold' tumors into immunoresponsive ones, improving the efficacy of immune checkpoint inhibitors.

In summary, a multi-pronged therapeutic approach targeting EMT has emerged, ranging from disrupting the TME to designing rational combination therapies (Table III). The future challenge lies in the precise clinical translation of these strategies, leveraging biomarkers to identify patient populations most likely to benefit.

Despite promising preclinical data, EMT-targeted therapies for PDAC face substantial translational barriers. Reliable EMT-specific biomarkers are lacking; traditional markers fail to capture EMT heterogeneity, single-cell sequencing-identified hybrid E/M states are hard to translate into routine assays (237) and CA19-9 reflects tumor burden but not EMT activity (238,239). Systemic toxicity and off-target effects further narrow the therapeutic window; EMT pathways (such as TGF-β, Wnt) have critical physiological roles, leading to severe side effects such as cardiovascular toxicity that halts anti-TGF-β therapies clinically (240), while core EMT-TFs (such as Snail and Twist) are 'undruggable' and upstream inhibition disrupts basal physiology (241).

Tumor cells exhibit robust compensatory mechanisms: blocking one EMT pathway activates parallel signaling networks, with combined PI3K/Akt and MAPK inhibition more effective than monotherapy and EMT-TME crosstalk offsets targeted effects via CAF-derived pro-EMT signals (242). Additionally, preclinical models (such as KPC mice) differ from human PDAC in TME, immune context and pharmacokinetics (243), while patient-specific factors (genetic heterogeneity and comorbidities) are underrepresented, exacerbating the translational gap. Addressing these challenges requires integrated strategies for biomarker development, improved drug specificity, compensatory network disruption and model refinement.

The present review emphasized that hybrid E/M states (rather than full EMT) confer the highest metastatic potential and chemoresistance in PDAC. However, the molecular markers that distinguish these states (such as specific EMT-TF, miRNA, or protein post-translational modification signatures) remain poorly defined. Current PDAC subtype classifications (classical compared with quasi-mesenchymal) also lack clear links to EMT trajectories; for example, high ZEB1 expression correlates with quasi-mesenchymal subtypes, but how this translates to therapeutic vulnerability is unclear. Future studies must use single-cell spatial multi-omics technologies (single-cell RNA sequencing combined with spatial proteomics) on patient-derived samples (primary tumors, CTCs, liver metastases) to map EMT phenotypic landscapes. This will enable identification of subtype-specific EMT drivers (such as Twist1 for classical PDAC, ZEB1 for quasi-mesenchymal PDAC) and development of companion diagnostics (such as circulating miR-200/ZEB1 ratio) to stratify patients for targeted therapy, avoiding the failure of unselected trials seen with earlier EMT inhibitors.

PDAC's desmoplastic stroma is not just a passive barrier but an active driver of EMT: CAFs secrete AREG to activate EGFR/Notch signaling in tumor cells, while PSCs deposit hyaluronan to amplify mechanical tension-driven EMT. Yet, the field still lacks a clear understanding of CAF subtype-specific regulation of EMT (myCAFs compared with inflammatory CAFs) and how EMT reciprocally reshapes stromal function (for example, tumor-derived PDGF activating PSCs). Current strategies targeting the stroma (such as Hh inhibitors) often trigger compensatory EMT via FGF signaling, highlighting the need for co-targeting approaches. Future work should use exosome tracing and cell-cell communication modeling to dissect paracrine loops (such as CAF-derived miR-146a activating Snail1) and develop rational combinations; for example, pairing CAF subtype-specific inhibitors (CHST15 antisense oligonucleotides) with EMT blockers (TGFβR1 inhibitors) to disrupt the 'EMT-stroma' positive feedback loop without destabilizing beneficial stromal functions (such as immune cell recruitment).

Two critical barriers limit clinical translation, as highlighted in the present review: The absence of dynamic EMT monitoring tools and poor in vivo efficacy of EMT inhibitors. For biomarkers, while CTCs with hybrid E/M phenotypes correlate with poor prognosis, current CTC detection methods (based on EpCAM enrichment) miss mesenchymal CTCs with low EpCAM expression. Future efforts should validate EMT-specific CTC markers (such as Vimentin/CD44v6) or circulating extracellular vesicle (EV) cargo (circFARP1, miR-146a) as surrogate endpoints for therapy response. For drug delivery, EMT inhibitors (such as HDAC inhibitors, TGF-β antagonists) suffer from low tumor penetration and off-target toxicity; potential solutions include ECM-targeted nanoparticles (decorin-functionalized carriers that bind collagen) or CAF-homing liposomes to deliver EMT-TF siRNAs (such as ZEB1 siRNA) directly to the stroma-tumor interface. Additionally, clinical trials must incorporate molecular stratification (such as TGF-β pathway activity, ZEB1 expression) to enrich for responsive patients, as seen in the phase I/II trial of STNM01 (a CHST15 inhibitor) which improved survival only in PDAC patients with high CAF levels.

A less emphasized finding in the present review is that modifiable risk factors (smoking, obesity, diabetes) account for 65.6% of PDAC cases in patients ≤60 years, yet how these factors drive EMT (such as chronic inflammation activating NF-κB/Snail1, hyperglycemia upregulating LINC00842/PGC-1α) remains understudied. Early PDAC lesions (PanIN) already exhibit EMT features, presenting a window for chemoprevention. Future research should explore repurposed agents targeting risk factor-driven EMT (such as metformin inhibiting mTOR/EMT in diabetic patients, aspirin blocking NF-κB/Snail1 in obese patients) in high-risk cohorts. Combining these agents with EMT monitoring tools (such as plasma EMT-related ncRNAs) could enable early intervention to halt PanIN progression to invasive PDAC, addressing the 'late diagnosis' dilemma that is the root cause of PDAC's poor prognosis.

Modifiable risk factors account for 65.6% of PDAC cases in patients ≤60 years, driving EMT via chronic inflammation or hyperglycemia. Early PanIN lesions already exhibit EMT features, offering a chemoprevention window. Future research should prioritize: i) Validating non-invasive EMT biomarkers for high-risk stratification; ii) evaluating repurposed agents (metformin, aspirin) in chemoprevention trials; iii) dissecting risk factor-EMT crosstalk to identify precise early targets. Combining these with dynamic EMT monitoring can halt PanIN progression to invasive PDAC, addressing late diagnosis.

In summary, advancing PDAC-EMT research requires a shift from 'broad EMT inhibition' to 'precision EMT modulation,' integrating insights into phenotypic heterogeneity, stromal crosstalk and early intervention. Only by addressing these gaps can EMT-targeted strategies fulfill their potential to transform PDAC from a lethal disease to a manageable one.